-v, --version
       Print scrub version and exit.

-r, --remove
       Remove the file after scrubbing.

-p, --pattern PATTERN
       Select the patterns to write.  nnsa selects patterns compliant with NNSA Policy Letter NAP-14.1-C;
       dod  selects patterns compliant with DoD 5220.22-M; bsi selects patterns recommended by the German
       Center of Security in Information Technologies (http://www.bsi.bund.de); old  selects  pre-version
       1.7  scrub  patterns;  and  fastold is old without the random pass.  gutmann is a 35-pass sequence
       described in Gutmann's paper cited below.  See STANDARDS below  for  more  detail.   random  is  a
       single  random  pass.   random2  is  two random passes.  schneier is the method described by Bruce
       Schneier in ''Applied Cryptography'' (1996) consisting of one 0x00 pass, one 0xff pass,  and  five
       random  passes.   pfitzner7  is Roy Pfitzner's 7-random-pass method.  pfitzner33 is Roy Pfitzner's
       33-random-pass method.  usarmy is the US Army AR380-19 method consisting of  one  0x00  pass,  one
       0xff pass, and a random pass.  Default: nnsa.

-b, --blocksize blocksize
       Perform  read(2)  and  write(2) calls using the specified blocksize (in bytes).  K, M, or G may be
       appended to the number to  change  the  units  to  KiBytes,  MiBytes,  or  GiBytes,  respectively.
       Default: 1M.

-f, --force
       Scrub even if target contains signature indicating it has already been scrubbed.

-S, --no-signature
       Do  not  write  scrub signature.  Scrub will not be able to ascertain if the disk has already been
       scrubbed.

-X, --freespace
       Create specified directory and fill it with files until write returns ENOSPC (file  system  full),
       then scrub the files as usual.  The size of each file can be set with -s, otherwise it will be the
       maximum file size creatable given the user's file size limit or 1g if umlimited.

-D, --dirent newname
       After scrubbing the file, scrub its name in the directory entry, then rename it to the  new  name.
       The  scrub  patterns  used on the directory entry are constrained by the operating system and thus
       are not compliant with cited standards.

-s, --device-size size
       Override the device size (in bytes). Without this option, scrub determines  media  capacity  using
       OS-specific  ioctl(2)  calls.   K,  M,  or  G may be appended to the number to change the units to
       KiBytes, MiBytes, or GiBytes, respectively.

-L, --no-link
       If file is a symbolic link, do not scrub the link target.  Do remove it, however, if  --remove  is
       specified.